Such multi-stage gas generators are already known from the prior art. One or more generator stages can be ignited depending on the respective demands. The same gas generator can thus be used in vehicle applications for different airbag modules and different vehicle types. However, with the aid of a corresponding control, a decision can also be made with a gas generator installed with an airbag module in a vehicle in dependence on the magnitude of the impact, on different accident conditions or on the situation of use, e.g. the manner of seat occupation, which generator stages are ignited at which time.
With such multi-stage gas generators, it must be prevented by the geometrical arrangement and the design of the individual generator stages that, when one generator stage is ignited, the propellant charge of the other generator is also unintentionally ignited (sympathetic ignition). The pressure housings of the individual generator stages must therefore be correspondingly insulated from one another, with the weight of the gas generator, however, simultaneously being kept as low as possible. Since such gas generators are mass products produced in very high volumes, the manufacture of the generator should moreover be as simple as possible despite these aforementioned demands. As few different parts as possible should in particular be used.